1. Field of the Invention
The present invention relates to a powered sliding device for a vehicle sliding door, and more particularly to a tension adjusting apparatus for use in a powered sliding device for a vehicle sliding door.
2. Description of the Related Art
There have been conventionally proposed many powered devices for sliding a sliding door which is slidably mounted to a vehicle body in a front-and-rear direction of the vehicle body under the power of the motor. For example, U.S. Pat. No. 5,046,283 discloses a powered sliding device which comprises a first wire drum connected with a first wire cable for pulling the sliding door forward, a second wire drum connected with a second wire cable for pulling the sliding door rearward and a tension spring provided between the first and second drums. The tension spring applies a predetermined tension to the wire cables by urging the first drum in the clockwise direction and urging the second drum in the counterclockwise direction.
The tension spring used in the powered sliding device has high resiliency so that it can resist a large force of the powered device with which the wire cable is pulled forward and rearward. The strong resiliency of the tension spring, however, causes difficulty in setting up the wire cable.
The present applicant (or Assignee) has proposed in U.S. patent application Ser. No. 08/702,956, UK Patent Application No. 9618139.1 and Korean Patent Application No. 96-36695 a tension mechanism which is divided into a first tension section for applying an initial tension to the wire cables after the completion of the set-up of the cables and a second tension section for absorbing looseness of the wire cables in use. In this tension mechanism, since the first tension section and the second tension section are independently provided at different positions, a plurality of processes are disadvantageously required for setting up the tension mechanism itself.